Abstract This work aims at the development of an electrochemical affinity biosensor for Pb(II) quantification using a platform that combines glassy carbon electrodes (GCE) and an aqueous dispersion of single-walled carbon nanotubes (SWCNT) covalently modified with cysteine residues (Cys). The biosensing protocol includes the accumulation of Pb(II) at the electrode surface through the affinity interaction promoted by Cys residues at open circuit potential, followed by the reduction of the accumulated Pb(II) at ‐0.900 V and the transduction step performed by linear sweep-adsorptive stripping voltammetry (LSAdSV) in a 0.020 M acetate buffer solution pH 5.00. There is a linear relationship between Pb(II) oxidation peak current and Pb(II) concentration. The dynamic linear range extends from 5.0 to 125.0 μg·L−1, exhibiting a sensitivity of 0.061 μAμg−1L and a detection limit of 0.69 μg·L−1. In addition, the selectivity of the biosensor was evaluated in the presence of high concentrations of possible interferents such as Cu(II), Cd(II), Ni(II), Hg(II), Rh(II), Ru(II), Zn(II), Ir(IV), Co(II) and As(III) demonstrating a high discrimination of Pb(II) in complex samples. The sensor was challenged with tap and rain water samples enriched with Pb(II), demonstrating outstanding properties in terms of recovery percentages showing an excellent agreement with ICP- MS.

中文翻译：

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半胱氨酸功能化生物纳米材料用于 Pb(II) 的亲和感测作为环境破坏的指标

摘要 本工作旨在开发一种用于 Pb(II) 定量的电化学亲和生物传感器，该传感器结合了玻璃碳电极 (GCE) 和用半胱氨酸残基 (Cys) 共价修饰的单壁碳纳米管 (SWCNT) 的水分散体。 . 生物传感协议包括通过 Cys 残基在开路电位促进的亲和相互作用在电极表面积累 Pb(II)，然后在 -0.900 V 减少积累的 Pb(II) 和线性执行的转导步骤0.020 M 醋酸盐缓冲溶液 pH 5.00 中的扫描吸附溶出伏安法 (LSAdSV)。Pb(II) 氧化峰值电流与 Pb(II) 浓度之间存在线性关系。动态线性范围从 5.0 扩展到 125.0 μg·L-1，灵敏度为 0。061 μAμg-1L，检测限为 0.69 μg·L-1。此外，在高浓度的可能干扰物如 Cu(II)、Cd(II)、Ni(II)、Hg(II)、Rh(II)、Ru(II) 存在下评估了生物传感器的选择性、Zn(II)、Ir(IV)、Co(II) 和 As(III) 证明了对复杂样品中 Pb(II) 的高度区分。该传感器接受了富含 Pb(II) 的自来水和雨水样品的挑战，在回收率方面表现出出色的特性，与 ICP-MS 非常吻合。